The role of CRE1 in a thermophilic fungus, Myceliophthora thermophila ATCC42464, was
studied using RNA interference. In the cre1-silenced strain C88, the filter paper hydrolyzing
activity and β-1,4-endoglucanase activity were 3.76-, and 1.31-fold higher, respectively, than
those in the parental strain when the strains were cultured in inducing medium for 6 days. The
activities of β-1,4-exoglucanase and cellobiase were 2.64-, and 5.59-fold higher, respectively,
than those in the parental strain when the strains were cultured for 5 days. Quantitative
reverse-transcription polymerase chain reaction showed that the gene expression of egl3, cbh1,
and cbh2 was significantly increased in transformant C88 compared with the wild-type strain.
Therefore, our findings suggest the feasibility of improving cellulase production by modifying
the regulator expression, and an attractive approach to increasing the total cellulase
productivity in thermophilic fungi.